At the widely watched Consumer Electronics Show in Vegas, the latest volley in the ongoing wireless carrier battled was unleashed. T-Mobile, in a move that has been hinted at by CEO John Legere, has offered to pay customers’ penalty fee with other carriers if they make the jump to them. The early-termination fee rebate could go as high as $650.

This comes partially in response to AT&T’s announcement last week, thought by many to be timed to upstage T-Mobile’s news, that they would pay T-Mobile subscribers $450 to switch to AT&T.

The only catch with T-Mobile’s new idea, which isn’t a big one, is that the customer must trade in their old phone, buy a new T-Mobile phone and move their phone number over. They call the new program, of which this is only the latest piece, their “Uncarrier” strategy. In recent months they have worked to upend the way the whole wireless-customer relationship works starting with removing contracts back in March of 2013. Over the summer they introduced “Jump” their early upgrade program, and free international roaming in October.

Time will tell if these tactics gain them more customers, and more loyalty from existing ones, and if it makes a dent in the way the other carriers do business.

For a full rundown of the carrier wars and how they are shaping up, read more here.